I'm playing with a Profoto Pro-7A 1200ws pack. When I plug a single lamp head into socket A and attempt to go beyond 1/2 power the unit does a long steady beep and a red light illuminates next to the max power level on the B channel power dial. The pack refuses to fire at anything above 1/2 (ex. full 1/1) on the A channel, if I bring the power level back down to 1/2 power it works fine. Swapping in a second head had the exact same behavior.
I feel like an idiot, it was in the manual. The B channel has to be set to 1/1 (max power) in order for channel A to go higher than 1/2.
From the manual:
"PLEASE NOTE! When the dial is positioned to release more
than 1/2 energy (within the area marked A ONLY) always
point the dial B towards the red indicator [16]. If this is not
done, the indicator lamp will light up. The audible signal will
sound and flash release will not be possible."
No need to feel that way - these older packs require a higher degree of manual control, and things that we would generally take for granted with more modern electronics would have been a "have to remember to remember that" at that time.
